They have a paralyzing fear of having their noble reputations tainted.
No, we have a paralyzing fear that Newt's victory of '94 and the subsequent increases we've enjoyed in the Congress have been destroyed by the bible thumpers...present company hopefully excepted.
About half of the coalition that elects republicans are Evangelical Christians. If your thought is that Evangelicals should show up every four years and vote for those parts of the Republican platform that you support and then quietly slink off and shut up with respect to the parts of the Republican platform that they support, that is not a coalition. You have to face the reality that, eventually, the Republican party is going to have to listen and respond to the desires of Evangelicals--or Evangelicals will have no reason to vote Republican.
The real test is coming up. Will Bush nominate and will the Republican Senators have the guts to confirm only original intenters to the US Supreme Court. My guess is no. At that point the coalition will begin to break apart.